Everyone has an idea of the celebrity they'd most like to party with given the opportunity, and right now we're totally going with Melissa McCarthy. She revealed on 'The Ellen Degeneres Show' just how out-of-control her behaviour gets at parties, particularly when there's alcohol involved.

Melissa McCarthy at the premiere for 'Chips'

The 47-year-old, who is set to star in the upcoming comedy 'Life of the Party' about a mother who returns to college to finish her degree, told Ellen that she was excited to attend her belated 60th birthday celebrations, but gave her fair warning about what she can expect from her.

'Dear Ellen, I wanna apologise to you in advance, or what I like to call a pre-apology, for my behaviour and if I dance challenge you', she said earnestly into the camera. 'And I will replenish the liquer I drink, but a chest bump is probably coming at you and I'm sorry but Happy Birthday.'

In regards to the dancing, she confesses that she gets 'dance competitive' at parties. 'I'm not proud of it', she added. Even when she was heavily pregnant with her youngest daughter Vivian, nothing could stop her taking over a club dancefloor after she had found a suitable disguise.

'I was eight months pregnant, I had a wig on, it was very strange', she recalled. 'I was very eccentric looking. We went to a club [and] nobody knew it was me and I danced as hard as I could dance because I was like, 'Nobody knows it's me'. I got in the middle of a huge dancefloor and danced hard. Eight months pregnant.'

And when she's not challenging people to a dance-off, she's greeting people with chest bumps - which is made awkward by the fact that she's usually shorter than everybody else.

'I'm always like, 'I'm not gonna do it', 'I'm not gonna do it', and I get too excited and I will chest bump people', she admitted. 'I got no business, I'm sure I should not be throwing this around. I'm never at the right height.'